Boiler.



Patented May 6, I902. J. M. MCCLELLON.

BOILER.

(Application fllad July 8, 1901.

(No Model.)

UNTTED STATES PATENT ()FTICE.

JAMES M. MCCLELLON, OF EVERETT, MASSACHUSETTS.

BOILER.

SPECILEIGATION forming part of Letters Patent No. 699,338, dated May 6, 1902.

' Application filed July 8,1901. Serial No. 67,451. (No model.)

To (0Z6 whom it may concern:

Beit known that LJAMES M. MCCLELLON,a citizen of the United States, residing at Everett, in the county of Middlesex and State of Massachusetts, have invented an Improvement in Boilers, of which the following description, in connection with the accompanying drawings, is a specification, like numerals on the drawings representing like parts. In the ordinary type of tubularboiler,wherein the products of combustion pass through tubes or flues which extend through the body of Waterin the boiler, the heating of the water in the boiler is accomplished by those gases which in their passage through the flue contact with the sides of the flue, and therefore the central portion of the column of heated gases passes through the fine without yielding up any of its heat to the water. In comparatively small boilers-sueh as are used in automobiles, steam -launehes, and fire-enginesit not infrequently happens that the temperature of the gases escaping through the top of the flues is from 700 to 900 Fahrenheit,thus showing that only a small portion of the heat generated has been absorbed by the water in the boiler.

It is the object of my'invention to improve this class of boilers by providing means whereby the temperature of the escaping gases may be reduced to practically that of the steam in the boiler, the result being that practically all the heat in the products of combustion above that of the steam is utilized in making steam, and this I accomplish by inclosing in each flue one or more water-tubes which have communication at their ends with the interior of the boiler-shell. Preferably the water-tubes will be arranged in contact with each other and will have a spiral arrangement in the flue, the outer tubes contacting with the interior of the flue, whereby the flue is divided into a plurality of spiral compartments. The products of combustion in passing up the flue are compelled to take the spiral or sinuous course and are therefore not only retained a longer time in the flue, but in their passage through the flue are either contacting with the walls of the fine or with the water-tubes inelosed therein. The

result is that the heating-surface .is materially increased, and a much greater economy is obtained.

In the drawings, Figure 1 illustrates avertical sectional view of a boiler, one of the tlues of the boiler being shown in section. Fig. 2 isa section on theline 2 2, Fig. 1. Fig. 3 is a section of the header.

The boiler sliell, which may be of any suitable construction, is designated by 3, it being shown as having secured to the lower portion thereof the apron 4,t'orming the usual chamber in which the burner or other heating medium is inclosed. Extending through the boiler are the usual flues, (designated generally by 5,) these fines being expanded at their ends into the ends of the boiler, as usual, and there being as many such fiues as is desired. For the sake ofclearncss of illustration only three of such flues have been illustrated in Fig. 1. Each flue incloses one or more water-tubes, which extend lengthwise of the flue and have communication at their ends with the exterior of the fine, and my preferred way of arrang ing these interior water-tubes is illustrated in Figs. 1 and 2. Preferably the ends of the water-tubes are connected to suitable headers, which extend across and are secured to the interior of the flues near their ends.

The headers are designated generally by 6, and they are made of any suitable material and have their ends curved, as at 7, to fit the interior of the flues. Each header is provided with a series of sockets of a size to receive the ends of the water-tubes, there being as many'such sockets as there are tubes inclosed in the flue. In this embodiment of my invention I employ three such water-tubes, and each header, therefore, has three sockets 8, into which the ends of the Water-tubes are secured in any suitable way.

Extending longitudinally through the header and transversely through the flue is an opening 9, which passes through the ends of each of the water-tubes, whereby each of said tubes has a free communication at its ends with the interior of the boiler-shell.

Preferably the central water-tube 10 will be straight, as seen in Fig. 1, and will extend centrally of the flue 5. The outside tubes 11 are preferably spirally arranged and are of such a size that they are in contact with the ter in the water-tubes 1O and ll, and as these water-tubes have free communication with the interior of the boiler at both their ends the steam generated in said tubes will escape atthe upper end thereof in the boiler-shell. Furthermore, because of the sinuous course which the heated gases are compelled to take they are retained longer in the fines and yield up a greater portion of their heat than if they passed straight from the tube. I have found by experiment that the gases issuing from the top of the fines have a temperature of only about 300 Fahrenheit instead of 700 or 800, as is the case when they pass directly through the fine.

To insure dry steam, I deem it advisable to place my upper header 6 some distance be- .low the top of the boiler, as seen in Fig. 1.

In the construction of my boiler the Watertubes will be brazed or otherwise secured to the headers, and the headers and water-tubes willthen he slipped into the fines and the headers secured thereto. When thus constructed, the fines may be expanded in the boiler, as usual.

WVhile I have illustrated herein one partic-' 5' tubes dividing the interior of the flue into two independent compartments.

2. In a tubular boiler, a plurality of fines extending therethrough, and a series of spirally-arranged water-tubes inclosed in and extending longitudinally of each of said fines.

3. In a tubular boiler, a boiler-shell, a plu- 'ality of fines therein, a plurality of watertubes extending longitudinally of each fine,

said water-tubes dividing the interior of the fines longitudinally into a plurality of sinuous compartments.

4. In a tubular boiler, a boiler-shell, a plurality of fines therein, and a plurality of Water-tubes extending longitudinally of each fine, said water-tubes dividing the interior of the fine longitudinally into a plurality of independent compartments. p

5. In a boiler, a boiler-shell, a plurality of fines therein, each of said fines having at each ity of fines therein, headers in the interior ofeach flue near each end thereof, a water-tube connecting the headers in each fine and extending centrally of the fine, anda port extending transversely through the flue and through each header whereby said water-tube has a free communication with the interior of the boiler-shell near each end thereof.

8. In a boiler, a boiler-shell having a pluralityot' fines therein, a header extending across the interior of eachfiue near each end thereof, spirally-arranged Water-tubes connecting the headers in each flue, and an opening extending transversely through the fine and each header and furnishing communication between the water-tnbes and the interior of the shell.

9. In a boiler, aboiler-shell having a plurality of fines, a series ofspirally-arranged water-tubes inclosed by each line, and extending longitudinally thereof, the water tubes of each series being in contact with each other and the outer tubes of the series engaging the inner wall of the fine, whereby each fine is divided into two sinuous; compartments.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES M. MCCLELLON. Witnesses:

LoUIs 0. SMITH, GEO. W. GREGORY. 

